"!!!1" was popularized on PPP by commenter Eyebleaf most often following the word playoffs. It has spread to include anything that requires extra emphasis and usually follows words that are capitalized.
The origin may have been a typo somewhere on the interwebs but here !!!1 is intentional and shows the truculence of the comment. !!!1 has been adopted as a sign of hope albeit irrational in times of despair. As eyebleaf would say PLAYOFFS!!!1